Generally, a strut-type suspension used for a front wheel of a four-wheeled vehicle has a structure in which a strut assembly incorporating a hydraulic shock absorber in an outer cylinder integrated with a main shaft is combined with a coil spring. Among such suspensions, there is a type in which when the strut assembly rotates together with the coil spring in the steering operation, the piston rod of the strut assembly rotates, and there is another type in which the piston rod does not rotate. In either type, there are cases where, instead of a rolling bearing, a synthetic resin-made thrust sliding bearing is used between a mechanism for mounting the strut assembly to the vehicle body and an upper spring seat member of the coil spring, so as to allow smooth rotation of the strut assembly.